Dental matrix



(No Model.)

G. A. MEISTER.

DENTAL MATRIX.

Patented Apr-.2, 1889-1 l/VVE/VTOR.

By W

ATTORNEYS.-

WITNESSES:

u; PETERS, PhuwLhhognyher, Walhlnglon, n. c.

' UNITED STATES PATENT OFFIC CHRIST. A. MEISTER, OF ALLENTOVVN, PENNSYLVANIA.

DENTAL MATRIX.

SPECIFICATION forming part of Letters Patent No. 400,587, dated April 2, 1889. Application filerl August 1888- Sen'al No. 282,795. (No model.)

To all whom it may concern.-

Be it known that I, CHRIST. A. MEISTER, of Allentown, in the county of Lehigh and State of Pennsylvania, have invented a new and Improved Dental Matrix, of which the following is a full, clear, and exact description.

The object of my invention is to provide a dental matrix and clamping means to be used on a tooth while'it is being filled; and it consists in the parts which will be, hereinafter described, and pointed out in the claims.

Reference is to be had to the accompanying drawings, forming a part of this specification,

in which similar letters of reference indicate corresponding parts in both the figures.

Figure 1 represents a top plan view of the matrix attached to a tooth, and Fig. 2 is a side View.

The matrix is preferably made of a flat band of resilient metal. The body or band proper, A, of the matrix is circular. The tooth is indicated by the letter M, and M is a cavity in said tooth. The bandis contracted at a, thence flared outward in opposite directions at b b, thence extended outward nearly at right angles, forming sides 6 e, and the two ends turned inward and united at g. o The outer side of the device at the point 9 is provided with a fixed collar, B, and the inner side thereof at said point 9 is provided with aplate, (J, fixed thereto. The sides 6 e are inclined inward from the main body outward. There is a screw-threaded bore through thecollar, point g, and plate aforesaid for the reception of a screw-threaded stem, D. The outer end of said stem is provided with a head, D, having a milled edge. To the inner end of the stem D is swiveled a cross-head, E, the outer ends, E, of which are T-shaped. Each side (2 e of the device is provided with a longitudinal slot, F, in which the said T- shaped ends of the cross-head are respectively engaged.

The operation is as follows: The band A of the matrix is engaged to a tooth to be filled in the manner shown in the drawings, having been fitted thereto by moving the cross-head in or out, as required, by means of the screw. To tighten the band on a tooth, the cross-head is moved inward against the taper sides e 6.

This action causes a contraction of the neck a and firmly clamps the band to the tooth, the pressure of the band on the tooth being equal at all points.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. A matrix for teeth, consisting of a band having a body for engaging a tooth, an integral extension of said' band, consisting of slotted inclined side pieces, a cross-head engaged in the slots of said sides, and means for actuating the cross -head, substantially as described.

2. A matrix for teeth, consisting of a band having a body for engaging a tooth, an integral extension of said band, consisting of slotted inclined side pieces, the outer united ends of said extensions being providedwith a screwthreaded opening, in combination with a screw-threaded stem having a cross-head swiv- 7o eled thereto, said cross-head being mounted in the slots of the side pieces aforesaid, substantially as described.

' 3. A matrix for teeth, comprising a toothgrasping band having extensions projecting 7 5 from its adjacent ends, a nut between outer ends of said extensions, a cross-head sliding upon said extensions to force them toward and from each other, and thereby contract or expand the ring, and a screw passing through the nut into engagement with the cross-head, substantially as set forth.

CHRIST. A. MEISTER. Witnesses:

NORMAN L. C. TROXELL, CHARLES H. HEFFNER. 

